Publications by authors named "Melanie Spedale"

Article Synopsis
  • Emerging research suggests that metformin may help prevent age-related macular degeneration (AMD) by affecting the gut microbiome and reducing choroidal neovascularization (CNV) in a mouse model.
  • The study involved administering metformin to specific pathogen-free male mice and assessing the size of CNV and changes in gene expression in the retinal pigment epithelium, as well as analyzing gut microbiota composition.
  • Results showed that metformin significantly reduced CNV size and macrophage infiltration, altered gene expression related to angiogenesis, and modified gut microbiota, indicating that the gut microbiome plays a role in metformin's protective effects against AMD.
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Unlabelled: In complex mammals, the importance and host-specificity of microbial communities have been demonstrated through their positive effects on host immune fitness or performance. However, whether host metabolic physiology homeostasis depends on a specific bacterial community exclusive to the host remains unclear. Here, we show that the coevolved host-specific microbiota is required to maintain diet-specific flexible and sufficient metabolic homeostasis through a high colonization rate, modulating gut metabolites, and related targets.

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Studies have begun to reveal significant connections between the gut microbiome and various retinal diseases, including age-related macular degeneration (AMD). As critical supporting tissues of the retina, the retinal pigment epithelium (RPE) and underlying choroid play a critical role in retinal homeostasis and degeneration. However, the relationship between the microbiome and RPE/choroid remains poorly understood, particularly in animal models of AMD.

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Trillions of microbial oscillators reside throughout the mammalian body, yet their contributions toward fundamental features of host circadian rhythms (CRs) have not been characterized. Here, we demonstrate that the microbiome contributes to host CRs in activity and thermoregulation. Mice devoid of microbes (germ-free, GF) exhibited higher-amplitude CRs in a light-dark cycle and longer circadian periods in constant darkness.

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Relationships between retinal disease, diet, and the gut microbiome have started to emerge. In particular, high-fat diets (HFDs) are associated with the prevalence and progression of several retinal diseases, including age-related macular degeneration (AMD) and diabetic retinopathy (DR). These effects are thought to be partly mediated by the gut microbiome, which modulates interactions between diet and host homeostasis.

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Purpose: Compelling new evidence reveals a close link between the gut microbiome and the pathogenesis of neovascular age-related macular degeneration (nAMD). Germ-free (GF) animal models are the current gold standard for studying host the microbe interactions in vivo; yet, no GF animal models of nAMD are available today. This protocol describes gnotobiotic operations and assembly for a laser-induced choroidal neovascularization (CNV) model in GF mice to study the gut microbiome in neovascular AMD.

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Background The potential role of the gut microbiome in cardiovascular diseases is increasingly evident. Arterial restenosis attributable to neointimal hyperplasia after cardiovascular procedures such as balloon angioplasty, stenting, and bypass surgery is a common cause of treatment failure, yet whether gut microbiota participate in the development of neointimal hyperplasia remains largely unknown. Methods and Results We performed fecal microbial transplantation from conventionally raised male C57BL/6 mice to age-, sex-, and strain-matched germ-free mice.

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Background: The microbiome has a functional role in a number of inflammatory processes and disease states. While neointimal hyperplasia development has been linked to inflammation, a direct role of the microbiota in neointimal hyperplasia has not yet been established. Germ-free (GF) mice are an invaluable model for studying causative links between commensal organisms and the host.

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